Corrosion-resistant high-carbon chromium bearing steel and smelting method

Abstract

The invention provides corrosion-resistant high-carbon chromium bearing steel and a smelting method, and relates to the technical field of bearing materials. The corrosion-resistant high-carbon chromium bearing steel is prepared from the following components in percentage by weight: 0.90 to 1.20 percent of C, 1.30 to 1.65 percent of Cr, 0.15 to 0.30 percent of Mo, 0.20 to 0.35 percent of Ni, 0.15 to 0.35 percent of Si, 0.25 to 0.45 percent of Mn, 0.05 to 0.15 percent of V, 0.01 to 0.03 percent of S, 0.01 to 0.03 percent of P and the balance of Fe and inevitable impurities. The metallographic structure of the bearing steel is uniform and fine pearlite and dispersively distributed carbides, and the average particle size of the carbides is 0.2-0.5 [mu] m. The bearing steel is made of high carbon and high chromium, and meanwhile, high-temperature-resistant elements such as molybdenum, nickel, silicon, manganese and vanadium are added into the steel, so that the corrosion resistance of the bearing steel is improved, the production cost is reduced, and the service life is prolonged; the characteristics of high hardness, difficulty in deformation, high abrasion resistance, high temperature resistance, corrosion resistance and the like are realized; and secondly, by optimizing chemical components and a smelting process, the cost is effectively controlled, and meanwhile, the high performance of the material is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of bearing materials, in particular to corrosion-resistant high-carbon chromium bearing steel and a smelting method. Background Art

[0002] Bearings are fixed components in machinery, used to maintain the center position of the shaft and control the relative motion of other components on the shaft. They are widely used in aviation, aerospace, national defense, large-scale mechanical equipment, and other fields. Bearing life is a key indicator for evaluating the quality of bearings, and precision and material are key indicators affecting bearing life. With the development of modern equipment manufacturing, the research on bearings has gradually shifted from precision to material research. Therefore, today's high-end bearing research is essentially the study of bearing materials.

[0003] Bearing steel is a type of steel used to manufacture the balls, rollers, and rings of rolling bearings. Traditional bearing steel, primarily based on low- or medium-carbon steel, offers excellent strength and toughness. However, it is susceptible to corrosion in harsh environments, such as those with moisture or corrosive media, which can affect the bearing's lifespan and performance. With the development of industry, higher requirements are being placed on the corrosion resistance of bearing steel. Existing improvements to this steel suffer from complex processes, high costs, and unsatisfactory corrosion resistance.

[0004] A search of the prior art revealed a Chinese patent application numbered "201610984602.4" for "a wear-resistant and high-temperature bearing steel." The patent discloses the following components by weight: C 0.7-1.2%, Si 0.25-0.55%, Ti 2.3-3.5%, Mn 2-3.6%, Mo 1.6-4.2%, S ≤ 0.005%, O ≤ 0.001%, P ≤ 0.0015%, Al 0.15-0.35%, Cr 0.1-1.5%, other unseparable impurities ≤ 0.002%, and the balance being Fe. The present invention utilizes titanium carbide, vanadium carbide, chromium carbide, and nickel, and incorporates high-temperature-resistant elements such as chromium, nickel, and titanium into the steel to form a protective film. This improves the bearing steel's high-temperature resistance, reduces production costs, and extends its service life. However, this bearing steel suffers from the aforementioned issue of insufficient corrosion resistance. Summary of the Invention

[0005] (1) Technical problems solved In view of the deficiencies in the prior art, the present invention provides corrosion-resistant high-carbon chromium bearing steel and a smelting method, which solve the problems raised by the above-mentioned background technology.

[0006] (2) Technical solution To achieve the above objectives, the present invention is implemented through the following technical scheme: corrosion-resistant high-carbon chromium bearing steel, including the following components in weight percentage: C: 0.90-1.20%, Cr: 1.30-1.65%, Mo: 0.15-0.30%, Ni: 0.20-0.35%, Si: 0.15-0.35%, Mn: 0.25-0.45%, V: 0.05-0.15%, S: 0.01-0.03%, P: 0.01-0.03%, and the balance is Fe and unavoidable impurities.

[0007] Preferably, the corrosion-resistant high carbon chromium bearing steel comprises the following components in weight percentage: C: 1.00-1.20%, Cr: 1.45-1.65%, Mo: 0.20-0.30%, Ni: 0.30-0.35%, Si: 0.30-0.35%, Mn: 0.40-0.45%, V: 0.10-0.15%, S: 0.02-0.03%, P: 0.02-0.03%, and the balance is Fe and unavoidable impurities.

[0008] Preferably, the corrosion-resistant high carbon chromium bearing steel comprises the following components in weight percentage: C: 1.00%, Cr: 1.45%, Mo: 0.20%, Ni: 0.30%, Si: 0.30%, Mn: 0.40%, V: 0.10%, S: 0.02%, P: 0.02%, and the remainder is Fe and unavoidable impurities.

[0009] Preferably, the metallographic structure of the bearing steel is uniform and fine pearlite and dispersed carbides, and the average particle size of the carbides is 0.2-0.5 μm.

[0010] The present invention further discloses a method for smelting corrosion-resistant high-carbon chromium bearing steel, comprising the following steps: Step 1: Ingredients: Accurately weigh various raw materials according to the designed chemical composition, including scrap steel, ferrochrome, ferromolybdenum, ferronickel, ferrosilicon, ferromanganese and ferrovanadium; Step 2: Install the furnace: Put the prepared raw materials into the electric furnace and spread a layer of lime on the bottom as slag-making material; Step 3: Melting: Power on and heat up. When the charge begins to melt, add an appropriate amount of deoxidizer for preliminary deoxidation. When the charge is basically melted, add refining agent for refining. Step 4: Deoxidation and alloying: After refining, deoxidizers and alloying elements are added for deoxidation and alloying to adjust the chemical composition of the steel; Step 5: Steel tapping: When the chemical composition and temperature of the molten steel meet the requirements, the molten steel is poured into a ladle, where it is calmed and then cast to obtain corrosion-resistant high-carbon chromium bearing steel.

[0011] Preferably, in step three, as the smelting proceeds, the temperature and atmosphere in the furnace are adjusted to maintain a slightly oxidizing atmosphere in the furnace to promote oxidation and removal of impurities.

[0012] Preferably, in step 3, the refining time is 30-40 minutes, and the refining temperature is 1550-1600°C.

[0013] Preferably, in step 4, the deoxidizer is added in multiple times and stirred evenly after each addition to reduce the oxygen content in the molten steel to below 10 ppm.

[0014] Preferably, in step five, the sedation time is 10-15 minutes.

[0015] Preferably, a heat treatment process is also included: (1) Heat treatment, including normalizing and quenching; (2) Tempering treatment.

[0016] (3) Beneficial effects The present invention provides corrosion-resistant high-carbon chromium bearing steel and a smelting method thereof. It has the following beneficial effects: 1. The present invention is made of high carbon and high chromium, and high temperature resistant elements such as molybdenum, nickel, silicon, manganese and vanadium are added to the steel, which improves the corrosion resistance of the bearing steel, reduces production costs and extends service life; it has the characteristics of high hardness, not easy to deform, strong wear resistance, high temperature resistance and corrosion resistance.

[0017] 2. By optimizing the chemical composition and smelting process, effective cost control is achieved while ensuring the high performance of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic flow chart of the smelting method of the present invention. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] Example 1: An embodiment of the present invention provides corrosion-resistant high-carbon chromium bearing steel, comprising the following components in weight percentage: C: 0.90%, Cr: 1.30%, Mo: 0.15%, Ni: 0.20%, Si: 0.15%, Mn: 0.25%, V: 0.05%, S: 0.01%, P: 0.01%, and the remainder is Fe and unavoidable impurities; wherein the metallographic structure of the bearing steel is uniform and fine pearlite and dispersed carbides, and the average particle size of the carbides is 0.2 μm.

[0021] like Figure 1 As shown, an embodiment of the present invention also provides a method for smelting corrosion-resistant high-carbon chromium bearing steel, comprising the following steps: Step 1: Ingredients: Accurately weigh various raw materials according to the designed chemical composition, including scrap steel, ferrochrome, ferromolybdenum, ferronickel, ferrosilicon, ferromanganese and ferrovanadium; Step 2: Install the furnace: Put the prepared raw materials into the electric furnace and spread a layer of lime on the bottom as slag-making material; Step 3: Melting: Power on and heat up. When the charge begins to melt, add an appropriate amount of deoxidizer for preliminary deoxidation. As the smelting progresses, adjust the temperature and atmosphere in the furnace to maintain a slightly oxidizing atmosphere to promote the oxidation and removal of impurities. When the charge is basically melted, add refining agent for refining. The refining time is 30 minutes and the refining temperature is 1550℃. Step 4: Deoxidation and alloying: After refining, deoxidizer and alloying elements are added for deoxidation and alloying to adjust the chemical composition of the steel; the deoxidizer is added in multiple times, and stirred evenly after each addition to reduce the oxygen content in the molten steel to below 10ppm.

[0022] Step 5: Steel tapping: When the chemical composition and temperature of the molten steel meet the requirements, the molten steel is poured into the ladle and calmed in the ladle for 10 minutes; Then casting is performed to obtain corrosion-resistant high-carbon chromium bearing steel.

[0023] Also includes heat treatment process: (1) Heat treatment, including normalizing and quenching, to ensure uniform structure of the material; (2) Tempering treatment to improve the toughness and corrosion resistance of the material.

[0024] Example 2: An embodiment of the present invention provides corrosion-resistant high-carbon chromium bearing steel, comprising the following components in weight percentage: C: 1.00%, Cr: 1.45%, Mo: 0.20%, Ni: 0.30%, Si: 0.30%, Mn: 0.40%, V: 0.10%, S: 0.02%, P: 0.02%, and the remainder is Fe and unavoidable impurities; wherein the metallographic structure of the bearing steel is uniform and fine pearlite and dispersed carbides, and the average particle size of the carbides is 0.4 μm.

[0025] like Figure 1 As shown, an embodiment of the present invention also provides a method for smelting corrosion-resistant high-carbon chromium bearing steel, comprising the following steps: Step 1: Ingredients: Accurately weigh various raw materials according to the designed chemical composition, including scrap steel, ferrochrome, ferromolybdenum, ferronickel, ferrosilicon, ferromanganese and ferrovanadium; Step 2: Install the furnace: Put the prepared raw materials into the electric furnace and spread a layer of lime on the bottom as slag-making material; Step 3: Melting: Power on and heat up. When the charge begins to melt, add an appropriate amount of deoxidizer for preliminary deoxidation. As the smelting progresses, adjust the temperature and atmosphere in the furnace to maintain a slightly oxidizing atmosphere to promote the oxidation and removal of impurities. When the charge is basically melted, add refining agent for refining. The refining time is 35 minutes and the refining temperature is 1580℃. Step 4: Deoxidation and alloying: After refining, deoxidizer and alloying elements are added for deoxidation and alloying to adjust the chemical composition of the steel; the deoxidizer is added in multiple times, and stirred evenly after each addition to reduce the oxygen content in the molten steel to below 10ppm.

[0026] Step 5: Steel tapping: When the chemical composition and temperature of the molten steel meet the requirements, the molten steel is poured into the ladle and calmed in the ladle for 12 minutes; Then casting is performed to obtain corrosion-resistant high-carbon chromium bearing steel.

[0027] Also includes heat treatment process: (1) Heat treatment, including normalizing and quenching, to ensure uniform structure of the material; (2) Tempering treatment to improve the toughness and corrosion resistance of the material.

[0028] Example 3: An embodiment of the present invention provides corrosion-resistant high-carbon chromium bearing steel, comprising the following components in weight percentage: C: 1.20%, Cr: 1.65%, Mo: 0.30%, Ni: 0.35%, Si: 0.35%, Mn: 0.45%, V: 0.15%, S: 0.03%, P: 0.03%, and the remainder is Fe and unavoidable impurities; wherein the metallographic structure of the bearing steel is uniform and fine pearlite and dispersed carbides, and the average particle size of the carbides is 0.5 μm.

[0029] like Figure 1 As shown, an embodiment of the present invention also provides a method for smelting corrosion-resistant high-carbon chromium bearing steel, comprising the following steps: Step 1: Ingredients: Accurately weigh various raw materials according to the designed chemical composition, including scrap steel, ferrochrome, ferromolybdenum, ferronickel, ferrosilicon, ferromanganese and ferrovanadium; Step 2: Install the furnace: Put the prepared raw materials into the electric furnace and spread a layer of lime on the bottom as slag-making material; Step 3: Melting: Power on and heat up. When the charge begins to melt, add an appropriate amount of deoxidizer for preliminary deoxidation. As the smelting progresses, adjust the temperature and atmosphere in the furnace to maintain a slightly oxidizing atmosphere to promote the oxidation and removal of impurities. When the charge is basically melted, add refining agent for refining. The refining time is 40 minutes and the refining temperature is 1600℃. Step 4: Deoxidation and alloying: After refining, deoxidizer and alloying elements are added for deoxidation and alloying to adjust the chemical composition of the steel; the deoxidizer is added in multiple times, and stirred evenly after each addition to reduce the oxygen content in the molten steel to below 10ppm.

[0030] Step 5: Steel tapping: When the chemical composition and temperature of the molten steel meet the requirements, the molten steel is poured into the ladle and calmed in the ladle for 15 minutes; Then casting is performed to obtain corrosion-resistant high-carbon chromium bearing steel.

[0031] Also includes heat treatment process: (1) Heat treatment, including normalizing and quenching, to ensure uniform structure of the material; (2) Tempering treatment to improve the toughness and corrosion resistance of the material.

[0032] Comparative Example: An embodiment of the present invention provides corrosion-resistant high-carbon chromium bearing steel, comprising the following components in weight percentage: C: 0.90%, Cr: 1.30%, Si: 0.15%, Mn: 0.25%, and the remainder being Fe and unavoidable impurities; wherein the metallographic structure of the bearing steel is uniform and fine pearlite and dispersed carbides, and the average particle size of the carbides is 0.2 μm.

[0033] like Figure 1 As shown, an embodiment of the present invention also provides a method for smelting corrosion-resistant high-carbon chromium bearing steel, comprising the following steps: Step 1: Ingredients: Accurately weigh various raw materials according to the designed chemical composition, including scrap steel, ferrochrome, ferrosilicon, and ferromanganese; Step 2: Install the furnace: Put the prepared raw materials into the electric furnace and spread a layer of lime on the bottom as slag-making material; Step 3: Melting: Turn on the power and heat up. When the charge begins to melt, add an appropriate amount of deoxidizer for preliminary deoxidation. When the charge is basically melted, add refining agent for refining. The refining time is 30 minutes and the refining temperature is 1550℃. Step 4: Deoxidation and alloying: After refining, deoxidizers and alloying elements are added for deoxidation and alloying to adjust the chemical composition of the steel.

[0034] Step 5: Steel tapping: When the chemical composition and temperature of the molten steel meet the requirements, the molten steel is poured into the ladle and calmed in the ladle for 10 minutes; Then casting is performed to obtain corrosion-resistant high-carbon chromium bearing steel.

[0035] Experimental example: The performance of the bearing steels prepared in Examples 1, 2, 3 and the comparative example was tested, and the results are shown in the following table: According to the above table, the bearing steels of Examples 1, 2 and 3 are superior to the comparative examples in hardness and tensile strength, and the corrosion resistance is significantly improved. This shows that the performance of the bearing steel can be significantly improved by precisely controlling the chemical composition and adopting specific smelting and heat treatment processes. In particular, Example 2 has achieved a relatively high level of hardness and tensile strength, and its corrosion resistance is also excellent, which may be related to its relatively high carbon content and the reasonable ratio of alloying elements. However, the comparative example has a lower carbon content and does not add enough alloying elements, resulting in its performance being significantly inferior to that of the embodiment. Therefore, the corrosion-resistant high-carbon chromium bearing steel and its smelting method provided by the present invention can meet the needs of high-performance bearing steel and have good application prospects.

[0036] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. Corrosion-resistant high carbon chromium bearing steel, characterized by: The invention comprises the following components in weight percentage: C: 0.90-1.20%, Cr: 1.30-1.65%, Mo: 0.15-0.30%, Ni: 0.20-0.35%, Si: 0.15-0.35%, Mn: 0.25-0.45%, V: 0.05-0.15%, S: 0.01-0.03%, P: 0.01-0.03%, and the balance is Fe and unavoidable impurities.

2. The corrosion-resistant high carbon chromium bearing steel according to claim 1, characterized in that: The invention comprises the following components in weight percentage: C: 1.00-1.20%, Cr: 1.45-1.65%, Mo: 0.20-0.30%, Ni: 0.30-0.35%, Si: 0.30-0.35%, Mn: 0.40-0.45%, V: 0.10-0.15%, S: 0.02-0.03%, P: 0.02-0.03%, and the balance is Fe and unavoidable impurities.

3. The corrosion-resistant high carbon chromium bearing steel according to claim 2, characterized in that: The invention comprises the following components in weight percentage: C: 1.00%, Cr: 1.45%, Mo: 0.20%, Ni: 0.30%, Si: 0.30%, Mn: 0.40%, V: 0.10%, S: 0.02%, P: 0.02%, and the balance is Fe and unavoidable impurities.

4. The corrosion-resistant high-carbon chromium bearing steel according to claim 3, characterized in that: The metallographic structure of the bearing steel is uniform and fine pearlite and dispersed carbides, and the average particle size of the carbides is 0.2-0.5 μm.

5. A method for smelting corrosion-resistant high-carbon chromium bearing steel, characterized by: The following steps are involved: Step 1: Ingredients: Accurately weigh various raw materials according to the designed chemical composition, including scrap steel, ferrochrome, ferromolybdenum, ferronickel, ferrosilicon, ferromanganese and ferrovanadium; Step 2: Install the furnace: Put the prepared raw materials into the electric furnace and spread a layer of lime on the bottom as slag-making material; Step 3: Melting: Power on and heat up. When the charge begins to melt, add an appropriate amount of deoxidizer for preliminary deoxidation. When the charge is basically melted, add refining agent for refining. Step 4: Deoxidation and alloying: After refining, deoxidizers and alloying elements are added for deoxidation and alloying to adjust the chemical composition of the steel; Step 5: Steel tapping: When the chemical composition and temperature of the molten steel meet the requirements, the molten steel is poured into a ladle, where it is calmed and then cast to obtain corrosion-resistant high-carbon chromium bearing steel.

6. The method for smelting corrosion-resistant high-carbon chromium bearing steel according to claim 5, characterized in that: In step three, as the smelting progresses, the temperature and atmosphere in the furnace are adjusted to maintain a slightly oxidizing atmosphere in the furnace to promote the oxidation and removal of impurities.

7. The method for smelting corrosion-resistant high-carbon chromium bearing steel according to claim 5, characterized in that: In step 3, the refining time is 30-40 minutes, and the refining temperature is 1550-1600°C.

8. The method for smelting corrosion-resistant high-carbon chromium bearing steel according to claim 5, characterized in that: In step 4, the deoxidizer is added in multiple times and stirred evenly after each addition to reduce the oxygen content in the molten steel to below 10 ppm.

9. The method for smelting corrosion-resistant high-carbon chromium bearing steel according to claim 5, characterized in that: In step 5, the sedation time is 10-15 minutes.

10. The method for smelting corrosion-resistant high-carbon chromium bearing steel according to claim 5, characterized in that: Also includes heat treatment process: (1) Heat treatment, including normalizing and quenching; (2) Tempering treatment.

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